Microbial Endophytes: Sustainable Approach for Managing Phosphorus Deficiency in Agricultural Soils

Abstract

Phosphorus (P) is the second most essential mineral nutrient after nitrogen for plant growth and development. The available form of P for plants is generally low even in fertile soils throughout the world. Phosphorus deficiency in soil is traditionally overcome by adding the phosphatic fertilizers, which also gets fixed into insoluble unavailable forms due to the high reactivity of soluble P with calcium, iron, or aluminum. The repeatedly applied fertilizer to agricultural fields led to the loss of soil fertility disturbs the soil microbial flora and causes pollution problems. Phosphate solubilizing microbial endophytes have played a significant role in phosphate solubilization. Endophytic microorganisms associated with different parts of the plants release organic acids into the soil, which solubilize the bound form of phosphate complexes and converts them into ortho-phosphate for uptake and utilization by plants. Inoculation of endophytic phosphate solubilizing microorganisms is a reliable technique for increasing soluble P in the soil leading to improved plant biomass and yield of crops. The rhizospheric bioengineering of bacterial strains to enhance phosphate solubilizing capacity will further help in improving the efficacy of biofertilizer inoculants for increasing crop productivity in sustainable agriculture. Thus, the use of plant growth-promoting bacterial endophytes as microbial biofertilizers provides a promising eco-friendly and cost-effective alternative to chemical fertilizers in sustainable agriculture.KeywordsEndophytesPlant colonizationPhosphate solubilizationPlant growth promotionBiofertilizers